Odontogenic infection is still a reality of the oral cavity, consequence of lack of access to preventive odontology, of bad treatment when the case is at the beginning or of ignorance about the complication associated to this infection. In this context, moderate and severe infection is a common occurrence in Clinical Dentistry, where septic tooth infection in patients with or without systemic alterations may lead to surgical procedures which are expensive for the public and private health system. The goal of this article is to present a series of clinical cases of odontogenic infection (moderate and/or severe) treated in Oral & Maxillofacial Surgery hospitals, presenting and discussing the many immediate and mediate forms of treatment, and also the possibility of preventive care.